1#
2# Copyright OpenEmbedded Contributors
3#
4# SPDX-License-Identifier: MIT
5#
6
7# This class is used to help the alternatives system which is useful when
8# multiple sources provide the same command. You can use update-alternatives
9# command directly in your recipe, but in most cases this class simplifies
10# that job.
11#
12# To use this class a number of variables should be defined:
13#
14# List all of the alternatives needed by a package:
15# ALTERNATIVE:<pkg> = "name1 name2 name3 ..."
16#
17#   i.e. ALTERNATIVE:busybox = "sh sed test bracket"
18#
19# The pathname of the link
20# ALTERNATIVE_LINK_NAME[name] = "target"
21#
22#   This is the name of the binary once it's been installed onto the runtime.
23#   This name is global to all split packages in this recipe, and should match
24#   other recipes with the same functionality.
25#   i.e. ALTERNATIVE_LINK_NAME[bracket] = "/usr/bin/["
26#
27# NOTE: If ALTERNATIVE_LINK_NAME is not defined, it defaults to ${bindir}/name
28#
29# The default link to create for all targets
30# ALTERNATIVE_TARGET = "target"
31#
32#   This is useful in a multicall binary case
33#   i.e. ALTERNATIVE_TARGET = "/bin/busybox"
34#
35# A non-default link to create for a target
36# ALTERNATIVE_TARGET[name] = "target"
37#
38#   This is the name of the binary as it's been installed by do_install
39#   i.e. ALTERNATIVE_TARGET[sh] = "/bin/bash"
40#
41# A package specific link for a target
42# ALTERNATIVE_TARGET_<pkg>[name] = "target"
43#
44#   This is useful when a recipe provides multiple alternatives for the
45#   same item.
46#
47# NOTE: If ALTERNATIVE_TARGET is not defined, it will inherit the value
48# from ALTERNATIVE_LINK_NAME.
49#
50# NOTE: If the ALTERNATIVE_LINK_NAME and ALTERNATIVE_TARGET are the same,
51# ALTERNATIVE_TARGET will have '.{BPN}' appended to it.  If the file
52# referenced has not been renamed, it will also be renamed.  (This avoids
53# the need to rename alternative files in the do_install step, but still
54# supports it if necessary for some reason.)
55#
56# The default priority for any alternatives
57# ALTERNATIVE_PRIORITY = "priority"
58#
59#   i.e. default is ALTERNATIVE_PRIORITY = "10"
60#
61# The non-default priority for a specific target
62# ALTERNATIVE_PRIORITY[name] = "priority"
63#
64# The package priority for a specific target
65# ALTERNATIVE_PRIORITY_<pkg>[name] = "priority"
66
67ALTERNATIVE_PRIORITY = "10"
68
69# We need special processing for vardeps because it can not work on
70# modified flag values.  So we aggregate the flags into a new variable
71# and include that variable in the set.
72UPDALTVARS  = "ALTERNATIVE ALTERNATIVE_LINK_NAME ALTERNATIVE_TARGET ALTERNATIVE_PRIORITY"
73
74PACKAGE_WRITE_DEPS += "virtual/update-alternatives-native"
75
76def gen_updatealternativesvardeps(d):
77    pkgs = (d.getVar("PACKAGES") or "").split()
78    vars = (d.getVar("UPDALTVARS") or "").split()
79
80    # First compute them for non_pkg versions
81    for v in vars:
82        for flag in sorted((d.getVarFlags(v) or {}).keys()):
83            if flag == "doc" or flag == "vardeps" or flag == "vardepsexp":
84                continue
85            d.appendVar('%s_VARDEPS' % (v), ' %s:%s' % (flag, d.getVarFlag(v, flag, False)))
86
87    for p in pkgs:
88        for v in vars:
89            for flag in sorted((d.getVarFlags("%s_%s" % (v,p)) or {}).keys()):
90                if flag == "doc" or flag == "vardeps" or flag == "vardepsexp":
91                    continue
92                d.appendVar('%s_VARDEPS_%s' % (v,p), ' %s:%s' % (flag, d.getVarFlag('%s_%s' % (v,p), flag, False)))
93
94def ua_extend_depends(d):
95    if not 'virtual/update-alternatives' in d.getVar('PROVIDES'):
96        d.appendVar('DEPENDS', ' virtual/${MLPREFIX}update-alternatives')
97
98def update_alternatives_enabled(d):
99    # Update Alternatives only works on target packages...
100    if bb.data.inherits_class('native', d) or \
101       bb.data.inherits_class('cross', d) or bb.data.inherits_class('crosssdk', d) or \
102       bb.data.inherits_class('cross-canadian', d):
103        return False
104
105    # Disable when targeting mingw32 (no target support)
106    if d.getVar("TARGET_OS") == "mingw32":
107        return False
108
109    return True
110
111python __anonymous() {
112    if not update_alternatives_enabled(d):
113        return
114
115    # compute special vardeps
116    gen_updatealternativesvardeps(d)
117
118    # extend the depends to include virtual/update-alternatives
119    ua_extend_depends(d)
120}
121
122def gen_updatealternativesvars(d):
123    ret = []
124    pkgs = (d.getVar("PACKAGES") or "").split()
125    vars = (d.getVar("UPDALTVARS") or "").split()
126
127    for v in vars:
128        ret.append(v + "_VARDEPS")
129
130    for p in pkgs:
131        for v in vars:
132            ret.append(v + ":" + p)
133            ret.append(v + "_VARDEPS_" + p)
134    return " ".join(ret)
135
136# Now the new stuff, we use a custom function to generate the right values
137populate_packages[vardeps] += "${UPDALTVARS} ${@gen_updatealternativesvars(d)}"
138
139# We need to do the rename after the image creation step, but before
140# the split and strip steps..  PACKAGE_PREPROCESS_FUNCS is the right
141# place for that.
142PACKAGE_PREPROCESS_FUNCS += "apply_update_alternative_renames"
143python apply_update_alternative_renames () {
144    if not update_alternatives_enabled(d):
145       return
146
147    import re
148
149    def update_files(alt_target, alt_target_rename, pkg, d):
150        f = d.getVar('FILES:' + pkg)
151        if f:
152            f = re.sub(r'(^|\s)%s(\s|$)' % re.escape (alt_target), r'\1%s\2' % alt_target_rename, f)
153            d.setVar('FILES:' + pkg, f)
154
155    # Check for deprecated usage...
156    pn = d.getVar('BPN')
157    if d.getVar('ALTERNATIVE_LINKS') != None:
158        bb.fatal('%s: Use of ALTERNATIVE_LINKS/ALTERNATIVE_PATH/ALTERNATIVE_NAME is no longer supported, please convert to the updated syntax, see update-alternatives.bbclass for more info.' % pn)
159
160    # Do actual update alternatives processing
161    pkgdest = d.getVar('PKGD')
162    for pkg in (d.getVar('PACKAGES') or "").split():
163        # If the src == dest, we know we need to rename the dest by appending ${BPN}
164        link_rename = []
165        for alt_name in (d.getVar('ALTERNATIVE:%s' % pkg) or "").split():
166            alt_link     = d.getVarFlag('ALTERNATIVE_LINK_NAME', alt_name)
167            if not alt_link:
168                alt_link = "%s/%s" % (d.getVar('bindir'), alt_name)
169                d.setVarFlag('ALTERNATIVE_LINK_NAME', alt_name, alt_link)
170            if alt_link.startswith(os.path.join(d.getVar('sysconfdir'), 'init.d')):
171                # Managing init scripts does not work (bug #10433), foremost
172                # because of a race with update-rc.d
173                bb.fatal("Using update-alternatives for managing SysV init scripts is not supported")
174
175            alt_target   = d.getVarFlag('ALTERNATIVE_TARGET_%s' % pkg, alt_name) or d.getVarFlag('ALTERNATIVE_TARGET', alt_name)
176            alt_target   = alt_target or d.getVar('ALTERNATIVE_TARGET_%s' % pkg) or d.getVar('ALTERNATIVE_TARGET') or alt_link
177            # Sometimes alt_target is specified as relative to the link name.
178            alt_target   = os.path.join(os.path.dirname(alt_link), alt_target)
179
180            # If the link and target are the same name, we need to rename the target.
181            if alt_link == alt_target:
182                src = '%s/%s' % (pkgdest, alt_target)
183                alt_target_rename = '%s.%s' % (alt_target, pn)
184                dest = '%s/%s' % (pkgdest, alt_target_rename)
185                if os.path.lexists(dest):
186                    bb.note('%s: Already renamed: %s' % (pn, alt_target_rename))
187                elif os.path.lexists(src):
188                    if os.path.islink(src):
189                        # Delay rename of links
190                        link_rename.append((alt_target, alt_target_rename))
191                    else:
192                        bb.note('%s: Rename %s -> %s' % (pn, alt_target, alt_target_rename))
193                        bb.utils.rename(src, dest)
194                        update_files(alt_target, alt_target_rename, pkg, d)
195                else:
196                    bb.warn("%s: alternative target (%s or %s) does not exist, skipping..." % (pn, alt_target, alt_target_rename))
197                    continue
198                d.setVarFlag('ALTERNATIVE_TARGET_%s' % pkg, alt_name, alt_target_rename)
199
200        # Process delayed link names
201        # Do these after other renames so we can correct broken links
202        for (alt_target, alt_target_rename) in link_rename:
203            src = '%s/%s' % (pkgdest, alt_target)
204            dest = '%s/%s' % (pkgdest, alt_target_rename)
205            link_target = oe.path.realpath(src, pkgdest, True)
206
207            if os.path.lexists(link_target):
208                # Ok, the link_target exists, we can rename
209                bb.note('%s: Rename (link) %s -> %s' % (pn, alt_target, alt_target_rename))
210                bb.utils.rename(src, dest)
211            else:
212                # Try to resolve the broken link to link.${BPN}
213                link_maybe = '%s.%s' % (os.readlink(src), pn)
214                if os.path.lexists(os.path.join(os.path.dirname(src), link_maybe)):
215                    # Ok, the renamed link target exists.. create a new link, and remove the original
216                    bb.note('%s: Creating new link %s -> %s' % (pn, alt_target_rename, link_maybe))
217                    os.symlink(link_maybe, dest)
218                    os.unlink(src)
219                else:
220                    bb.warn('%s: Unable to resolve dangling symlink: %s' % (pn, alt_target))
221                    continue
222            update_files(alt_target, alt_target_rename, pkg, d)
223}
224
225def update_alternatives_alt_targets(d, pkg):
226    """
227    Returns the update-alternatives metadata for a package.
228
229    The returned format is a list of tuples where the tuple contains:
230    alt_name:     The binary name
231    alt_link:     The path for the binary (Shared by different packages)
232    alt_target:   The path for the renamed binary (Unique per package)
233    alt_priority: The priority of the alt_target
234
235    All the alt_targets will be installed into the sysroot. The alt_link is
236    a symlink pointing to the alt_target with the highest priority.
237    """
238
239    pn = d.getVar('BPN')
240    pkgdest = d.getVar('PKGD')
241    updates = list()
242    for alt_name in (d.getVar('ALTERNATIVE:%s' % pkg) or "").split():
243        alt_link     = d.getVarFlag('ALTERNATIVE_LINK_NAME', alt_name)
244        alt_target   = d.getVarFlag('ALTERNATIVE_TARGET_%s' % pkg, alt_name) or \
245                       d.getVarFlag('ALTERNATIVE_TARGET', alt_name) or \
246                       d.getVar('ALTERNATIVE_TARGET_%s' % pkg) or \
247                       d.getVar('ALTERNATIVE_TARGET') or \
248                       alt_link
249        alt_priority = d.getVarFlag('ALTERNATIVE_PRIORITY_%s' % pkg,  alt_name) or \
250                       d.getVarFlag('ALTERNATIVE_PRIORITY',  alt_name) or \
251                       d.getVar('ALTERNATIVE_PRIORITY_%s' % pkg) or  \
252                       d.getVar('ALTERNATIVE_PRIORITY')
253
254        # This shouldn't trigger, as it should have been resolved earlier!
255        if alt_link == alt_target:
256            bb.note('alt_link == alt_target: %s == %s -- correcting, this should not happen!' % (alt_link, alt_target))
257            alt_target = '%s.%s' % (alt_target, pn)
258
259        if not os.path.lexists('%s/%s' % (pkgdest, alt_target)):
260            bb.warn('%s: NOT adding alternative provide %s: %s does not exist' % (pn, alt_link, alt_target))
261            continue
262
263        alt_target = os.path.normpath(alt_target)
264        updates.append( (alt_name, alt_link, alt_target, alt_priority) )
265
266    return updates
267
268PACKAGESPLITFUNCS =+ "populate_packages_updatealternatives"
269
270python populate_packages_updatealternatives () {
271    if not update_alternatives_enabled(d):
272        return
273
274    # Do actual update alternatives processing
275    for pkg in (d.getVar('PACKAGES') or "").split():
276        # Create post install/removal scripts
277        alt_setup_links = ""
278        alt_remove_links = ""
279        updates = update_alternatives_alt_targets(d, pkg)
280        for alt_name, alt_link, alt_target, alt_priority in updates:
281            alt_setup_links  += '\tupdate-alternatives --install %s %s %s %s\n' % (alt_link, alt_name, alt_target, alt_priority)
282            alt_remove_links += '\tupdate-alternatives --remove  %s %s\n' % (alt_name, alt_target)
283
284        if alt_setup_links:
285            # RDEPENDS setup
286            provider = d.getVar('VIRTUAL-RUNTIME_update-alternatives')
287            if provider:
288                #bb.note('adding runtime requirement for update-alternatives for %s' % pkg)
289                d.appendVar('RDEPENDS:%s' % pkg, ' ' + d.getVar('MLPREFIX', False) + provider)
290
291            bb.note('adding update-alternatives calls to postinst/prerm for %s' % pkg)
292            bb.note('%s' % alt_setup_links)
293            postinst = d.getVar('pkg_postinst:%s' % pkg)
294            if postinst:
295                postinst = alt_setup_links + postinst
296            else:
297                postinst = '#!/bin/sh\n' + alt_setup_links
298            d.setVar('pkg_postinst:%s' % pkg, postinst)
299
300            bb.note('%s' % alt_remove_links)
301            prerm = d.getVar('pkg_prerm:%s' % pkg) or '#!/bin/sh\n'
302            prerm += alt_remove_links
303            d.setVar('pkg_prerm:%s' % pkg, prerm)
304}
305
306python package_do_filedeps:append () {
307    if update_alternatives_enabled(d):
308        apply_update_alternative_provides(d)
309}
310
311def apply_update_alternative_provides(d):
312    pn = d.getVar('BPN')
313    pkgdest = d.getVar('PKGDEST')
314
315    for pkg in d.getVar('PACKAGES').split():
316        for alt_name in (d.getVar('ALTERNATIVE:%s' % pkg) or "").split():
317            alt_link     = d.getVarFlag('ALTERNATIVE_LINK_NAME', alt_name)
318            alt_target   = d.getVarFlag('ALTERNATIVE_TARGET_%s' % pkg, alt_name) or d.getVarFlag('ALTERNATIVE_TARGET', alt_name)
319            alt_target   = alt_target or d.getVar('ALTERNATIVE_TARGET_%s' % pkg) or d.getVar('ALTERNATIVE_TARGET') or alt_link
320
321            if alt_link == alt_target:
322                bb.warn('%s: alt_link == alt_target: %s == %s' % (pn, alt_link, alt_target))
323                alt_target = '%s.%s' % (alt_target, pn)
324
325            if not os.path.lexists('%s/%s/%s' % (pkgdest, pkg, alt_target)):
326                continue
327
328            # Add file provide
329            trans_target = oe.package.file_translate(alt_target)
330            d.appendVar('FILERPROVIDES:%s:%s' % (trans_target, pkg), " " + alt_link)
331            if not trans_target in (d.getVar('FILERPROVIDESFLIST:%s' % pkg) or ""):
332                d.appendVar('FILERPROVIDESFLIST:%s' % pkg, " " + trans_target)
333
334